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      <title>消息堆积原因与处理方法 - 交互式测验</title>
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          <div class="quiz-container">
            <div class="quiz-header">
              <h1>消息堆积原因与处理方法 - 交互式测验</h1>
              <p>检验你对文档内容的理解程度</p>
            </div>
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      <script>
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  {
    "question": "根据文档，消息堆积的根本原因是什么？",
    "options": [
      "生产者与消费者之间的网络延迟过高。",
      "消息队列Broker发生故障，无法转发消息。",
      "生产者发送消息的速率超过了消费者消费消息的速率。",
      "消费者处理逻辑过于简单，导致资源浪费。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "文档开篇即明确定义，消息堆积的核心问题在于生产与消费速率失衡。当生产者发送消息的速度快于消费者处理消息的速度时，未被处理的消息就会在Broker中积压，形成堆积。",
    "source": "文档中「导致消息堆积的常见原因」部分开篇定义",
    "hint": "可以从供需关系的角度思考，当供应（生产）远大于需求（消费）时会发生什么？"
  },
  {
    "question": "以下哪项不属于文档中提到的因“消费者处理能力不足”而导致消息堆积的原因？",
    "options": [
      "消费组中的消费者实例数量少于Topic的队列数。",
      "消费逻辑中包含复杂的计算或远程调用，导致单条消息处理时间过长。",
      "促销活动或秒杀导致业务流量突增。",
      "消费者的线程池大小设置过小，导致并发处理能力低下。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "促销活动或秒杀导致的流量突增属于“生产峰值或突发流量”的范畴，是生产者侧的原因，而非消费者自身处理能力的问题。而其他选项，如处理耗时长、实例数量不足、线程池配置不合理，都直接归因于消费者自身的处理能力不足。",
    "source": "文档中「1. 消费者处理能力不足」和「2. 生产峰值或突发流量」部分",
    "hint": "这个问题要求区分原因是出在“消费能力”一侧，还是“生产流量”一侧。"
  },
  {
    "question": "当消息出现严重堆积时，文档推荐的哪种紧急措施可以最直接、快速地提升消费能力？",
    "options": [
      "通过水平扩展，增加消费者实例的数量。",
      "在生产者端引入限流机制，减缓消息发送速率。",
      "优化消费逻辑中的数据库查询语句。",
      "重新设计Topic和队列，将不同业务分拆。"
    ],
    "correctAnswerIndex": 0,
    "explanation": "在紧急情况下，增加消费者实例数量（水平扩展）是应对突发流量和处理积压消息最直接有效的方法之一。它可以立即增加并行的处理单元，从而成倍提高整体的消费吞吐量。其他选项虽然也可能有效，但通常不属于能立即生效的“紧急措施”。",
    "source": "文档中「处理消息堆积的紧急措施」下的「1. 提升消费能力」部分",
    "hint": "紧急情况下，什么操作能最快地“增加人手”来处理积压的工作？"
  },
  {
    "question": "在处理消息堆积的紧急情况时，如果无法立即提升消费能力，文档提出了一种“临时存储策略”。以下哪个操作最符合该策略？",
    "options": [
      "停止生产者应用，阻止新消息进入队列。",
      "将积压的消息消费后转储到另一个备用存储系统（如数据库），待高峰过后另行处理。",
      "将消费者的重试次数设置为无限，确保消息最终能被处理。",
      "立即丢弃所有积压的非核心消息，以保证核心业务的流畅。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "该策略的核心思想是“腾挪数据，缓解压力”。通过将消息快速地从消息队列中“搬运”到另一个能承受压力的存储系统中，可以迅速降低队列的积压水位，让系统恢复正常。之后再通过离线任务等方式对转储的数据进行补偿处理。这既避免了数据丢失，也缓解了燃眉之急。",
    "source": "文档中「处理消息堆积的紧急措施」下的「4. 临时存储策略」部分",
    "hint": "当主干道严重拥堵时，一种紧急疏导交通的方式是什么？"
  },
  {
    "question": "从预防消息堆积的长期解决方案来看，以下哪项属于“合理的系统架构设计”范畴？",
    "options": [
      "为所有消费者设置一个超大的、固定的线程池。",
      "将所有类型的业务消息都发送到同一个Topic，方便统一管理。",
      "根据业务特性将不同处理速度的业务分拆到不同的Topic中。",
      "在消费端代码中硬编码所有依赖服务的IP地址以提升性能。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "将处理速度不同的业务（如快、慢业务）分离到不同的Topic，可以为它们配置独立的消费资源和策略，避免慢业务拖慢快业务的消费速度。这是在架构层面避免资源争抢和相互影响的有效手段，属于优秀的设计实践。",
    "source": "文档中「预防消息堆积的长期解决方案」下的「1. 合理的系统架构设计」部分",
    "hint": "在一条公路上，如何设计才能让快车和慢车互不影响，各自高效通行？"
  },
  {
    "question": "为了建立有效的监控预警体系以预防消息堆积，文档强调了需要关注多个关键指标。以下哪个组合是最核心的监控指标？",
    "options": [
      "消费者的部署机器的操作系统版本。",
      "消息积压量及其增长率、生产速率与消费速率的对比。",
      "Broker节点的磁盘总容量和剩余空间。",
      "消息生产者的代码行数和圈复杂度。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "消息积压量是衡量堆积程度最直接的指标，其增长率则能反映堆积趋势。同时，对比生产和消费速率，可以从根本上判断系统是否处于供需平衡的健康状态。这两个指标组合是监控消息队列健康状况、预警堆积风险的核心。",
    "source": "文档中「预防消息堆积的长期解决方案」下的「3. 监控与预警体系」部分",
    "hint": "如果要监控一个水库的水位安全，最需要关注的是哪几个数据？"
  },
  {
    "question": "文档中提到了“业务降级”作为一种容灾策略。在消费者端，这通常意味着什么？",
    "options": [
      "当正常处理逻辑失败时，执行一个备用的、简化的处理逻辑（Fallback），保证部分核心功能可用。",
      "无视所有错误，强制确认所有消息已被消费，以快速清空队列。",
      "消费者在检测到堆积时自动关机，等待人工干预。",
      "将消息的优先级动态调至最低，让其在队列末尾等待。"
    ],
    "correctAnswerIndex": 0,
    "explanation": "业务降级是一种牺牲非核心功能、保全核心功能的策略。在消费者端，当正常流程（如调用多个外部API）受阻时，可以切换到一个备用方案（如只更新本地状态或记录日志），避免单点故障导致整个消费流程阻塞，从而防止消息积压加剧。",
    "source": "文档中「预防消息堆积的长期解决方案」下的「4. 容灾与降级策略」部分",
    "hint": "当汽车的一个非关键零件（如空调）坏了，为了能继续把车开到目的地，驾驶员会怎么做？"
  }
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            const wrongCount = answeredCount - correctCount;
            const skippedCount = totalQuestions - answeredCount;
            const accuracy = totalQuestions > 0 ? Math.round((correctCount / totalQuestions) * 100) : 0;
            const errorRate = totalQuestions > 0 ? Math.round((wrongCount / totalQuestions) * 100) : 0;

            const finalScoreHtml =
                '<div class="final-score-container">' +
                '<h2>答题报告</h2>' +
                '<div class="score-summary">' +
                '<div class="score-card">' +
                '<h3>得分</h3>' +
                '<p>' + correctCount + ' / ' + totalQuestions + '</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>正确率</h3>' +
                '<p>' + accuracy + '%</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>错误率</h3>' +
                '<p>' + errorRate + '%</p>' +
                '</div>' +
                '<div class="score-card score-details">' +
                '<table>' +
                '<tr><td>正确</td><td>' + correctCount + '</td></tr>' +
                '<tr><td>错误</td><td>' + wrongCount + '</td></tr>' +
                '<tr><td>未答</td><td>' + skippedCount + '</td></tr>' +
                '</table>' +
                '</div>' +
                '</div>' +
                '<div class="report-actions">' +
                '<button id="review-btn">回顾测验</button>' +
                '<button class="primary" onclick="location.reload()">再试一次</button>' +
                '</div>' +
                '</div>';

            let reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }
            quizContentEl.insertAdjacentHTML('beforeend', finalScoreHtml);
            document.getElementById('review-btn').addEventListener('click', reviewQuiz);
        }

        function reviewQuiz() {
            const reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }

            document.querySelector('.quiz-body').style.display = 'block';
            document.getElementById('quiz-footer').style.display = 'flex';
            
            currentQuestionIndex = 0;
            loadQuestion();
            updateNavigationButtons(); // Ensure nav buttons are correctly displayed
        }

        // Event Delegation for options
        optionsListEl.addEventListener('click', (event) => {
            if (event.target && event.target.matches('li.option-item')) {
                // Check if the question has already been answered
                if (userAnswers[currentQuestionIndex] === null) {
                    const selectedIndex = parseInt(event.target.dataset.index, 10);
                    selectOption(selectedIndex);
                }
            }
        });

        prevBtn.addEventListener('click', goToPreviousQuestion);
        nextBtn.addEventListener('click', goToNextQuestion);
        hintBtn.addEventListener('click', showHint);
        
        // 初始加载
        loadQuestion();
      </script>
    </body>
    </html>
  